1. Field of the Technology
The invention relates to the field of network communication technology, and particularly to methods and systems for implementing a message service based on IP Multimedia Subsystem (IMS), IMS-based Serving-Call Session Control Function (S-CSCF), IP-Short Message-Gateway (IP-SM-GW).
2. Background of the Technology
Along with development of broadband networks, mobile communications go beyond traditional voice communication. Multimedia services in association with various media types, such as audio, video, picture and text, will be developed gradually. By combining with such data services as presence, short message, WEB browsing, location information, PUSH and file sharing services, mobile communications can meet various demands of mobile subscribers.
Driven by various applications, standardization organizations of 3rd Generation Partnership Project (3GPP) and 3rd Generation Partnership Project 2 (3GPP2) put forward an architecture based on IMS successively, the objective thereof is to provide a standardized open architecture in mobile networks to implement various multimedia applications, and provide mobile subscribers with more choices and experiences.
In 3GPP Release 5 (R5), an IMS domain is introduced. The IMS domain is overlaid on the Packet Switched (PS) domain network and includes Call Session Control Function (CSCF), Media Gateway Control Function (MGCF), Media Resources Function (MRF) and Home Subscriber Server (HSS) etc. The CSCF may be categorized into S-CSCF. Proxy-CSCF (P-CSCF) and Interrogating-CSCF (I-CSCF). The S-CSCF is a service switching center of IMS for executing session control, maintaining session status, managing user information and generating charging information, and so on. The P-CSCF, as an access point from which a terminal subscriber accesses the IMS, is used for registering a subscriber, controlling the Quality of Service (QoS) and conducting the security management, and so on. The I-CSCF is responsible for interworking between the IMS domains, managing assignment of the S-CSCF, hiding the network topology and the configuration information from the outside and generating billing data, and so on. The MGCF implements the interworking between an IMS network and other networks by controlling gateways. The MRF is used for providing media resources, such as receiving and playing voices, coding and decoding as well as multimedia conference bridges. The HSS is a user database which stores subscription data and configuration information of IMS subscribers, and so on.
Since the architecture of IMS network is independent of the bearer network of lower level, the IMS network defined by the 3GPP may be applied to other packet networks apart from the packet domain network defined by the 3GPP, such as a packet network, a Wireless Local Area Network (WLAN) and a Next Generation Network (NGN) defined in the 3GPP2, such that the IMS network is independent of the types of terminals and the types of access networks. Therefore, the IMS may be applied to networks and applications related to the 3GPP, and also may be applied to other types of services and applications of access networks and bearer networks. In this way, the IMS provides the future multimedia applications with a universal service enablement platform, which is an important step of system evolution to All IP Network services providing system.
At present, the 3GPP defines two kinds of IMS-based message service: an Immediate Message service and a Session Based Message service.
The method for implementing the Immediate Message service is hereinafter described in detail with reference to the accompanying drawings.
When a called subscriber UE#2 has registered in the IMS domain, a process of sending an immediate message from an IMS-based calling subscriber UE#1 to UE#2 is as shown in FIG. 1, which includes the following steps.
Step 101. UE#1 edits a message containing multimedia contents and needs to send the message to UE#2 (UE#1 generates the multimedia content to be sent).
Step 102 UE#1 sends to a P-CSCF#1 corresponding to UE#1 a MESSAGE request, the multimedia contents edited by UE#1 is contained in a message body of the MESSAGE request.
Step 103. P-CSCF#1 implements the MESSAGE request to an S-CSCF#1 in which UE#1 currently registers.
Step 104. S-CSCF#1 implements Service control.
To be specific, S-CSCF#1 checks a length and a type of the message in the MESSAGE request according to an operator strategy configured in S-CSCF#1. Besides, S-CSCF#1 may trigger a service logic matching the MESSAGE request according to service logics to which UE#1 has subscribed; for example, the MESSAGE request is routed to an Application Server (AS) for the subsequent processing.
Step 105. S-CSCF#1 forwards the MESSAGE request to I-CSCF-#2. In this step, S-CSCF#1 determines I-CSCF#2 according to information related to called subscriber contained in the MESSAGE request.
Step 106. I-CSCF#2 inquires about the route (Location Query procedure with HSS), i.e. requests address information of S-CSCF of UE#2 from an HSS. The address information of S-CSCF of UE#2 is the address information of S-CSCF#2.
Step 107. I-CSCF#2 forwards the MESSAGE request to S-CSCF#2.
Step 108. S-CSCF#2 implements Service control.
To be specific, S-CSCF#2 checks a length and a type of the message in the MESSAGE request according to an operator strategy configured in S-CSCF#2; besides, S-CSCF#2 may trigger a service logic matching the MESSAGE request, for example, the MESSAGE request is routed to an AS for the subsequent processing. If it is impossible to deliver the message when an activated service currently exists in UE#2, such as a service for hiding son kind of messages, the AS may return an error response to S-CSCF#2.
Step 109. S-CSCF#2 forwards the MESSAGE request to the current P-CSCF#2 of UE#2.
Step 110. Upon receiving the MESSAGE request. P-CSCF#2 forwards the MESSAGE request to UE#2; UE#2 displays multimedia contents to the terminal Subscriber (UE#2 renders multimedia content).
Steps 111 to 116. UE#2 returns to UE#1 a response message (200 OK) for accepting the MESSAGE request.
When UE#2 has not registered in the IMS domain but has subscribed to a “service of unregistered state”, a process of sending an immediate message from an IMS-based calling subscriber UE#1 to a called subscriber UE#2 is as shown in FIG. 2, which includes the following steps.
Step 210. UE#1 edits a message containing multimedia contents and needs to send the message to UE#2.
Step 202. UE#1 sends to a P-CSCF#1 corresponding to UE#1 a MESSAGE request, the multimedia contents edited by UE#1 is contained in a message body of the MESSAGE request.
Step 203. P-CSCF#1 forwards the MESSAGE request to S-CSCF#1 in which UE#1 currently registers.
Step 204. S-CSCF#1 checks a length and a type of the message in the MESSAGE request according to an operator strategy configured in S-CSCF#1; besides, S-CSCF#1 may trigger a service logic matching the MESSAGE request, for example, the MESSAGE request is routed to an AS for the subsequent processing.
Step 205. S-CSCF#1 forwards the MESSAGE request to I-CSCF#2.
Step 206. I-CSCF#2 inquires about the route, i.e. I-CSCF#2 requests the address information of the S-CSCF corresponding to UE#2 from an HSS; the address information of the S-CSCF corresponding to UE#2 is the address information of S-CSCF#2.
At this point, since UE#2 has not registered in the IMS domain, the HSS checks whether the unregistered UE#2 has subscribed to a “service of unregistered state”, if so, the HSS designates a certain S-CSCF as S-CSCF#2 and returns the address information of this S-CSCF#2 to I-CSCF#2; alternatively, the HSS returns the required capability information of S-CSCF to I-CSCF#2, and I-CSCF#2 selects an appropriate S-CSCF as S-CSCF#2 by itself
Then, I-CSCF#2 forwards the MESSAGE request to S-CSCF#2; after receiving the MESSAGE request and downloading the data related to UE#2 from the HSS according to the subscriber identifier of UE#2, S-CSCF#2 triggers the matched service control logic according to the “service of unregistered state” to which the subscriber has subscribed, and forwards the MESSAGE request to an AS; the AS makes the subsequent processing. If the subscriber has not subscribed to a “service of unregistered state”, the HSS returns a route-inquiring failure response.
Step 207. I-CSCF#2 towards the MESSAGE request to S-CSCF#2.
Step 208. S-CSCF#2 checks a length and a type of the message in the MESSAGE request according to an operator strategy configured in S-CSCF#2, and further checks whether an activated service that will stop the message being delivered exists, such as an activated service for hiding some kind of messages. Besides, S-CSCF#2 may trigger a service logic matching the MESSAGE request, for example, the MESSAGE request is routed to an AS for the subsequent processing. Eventually, the MESSAGE request is sent to UE#2.
Steps 209 to 212. S-CSCF#2 returns to UE#1 the response message for accepting the MESSAGE request returned from UE#2.
At present, the 3GPP sets forth a network architecture illustrating the interworking between an IMS-based message service and the traditional short message service, which is as shown in FIG. 3.
In FIG. 3, the Short Message Entity (SME), Short Message-Service Center (SM-SC), Gateway Mobile Switch Center/Short Message-InterWorking Mobile Switch Center (GMSC/SM-IWMSC), Home Subscriber Server/Home Location Register (HSS/HLR), Charging Gateway Function/Charging Data Function (CGF/CDF) and Online Charging System (OCS) are function entities for implementing short message service (SMS) in the existing mobile networks.
The SM-SC is used for storing short messages; the GMSC is used for inquiring routing information) from the HSS/HLR when a mobile subscriber is receiving a short message; the SM-IWMSC is used for checking whether a short message is allowed to be sent to its home SM-SC when a mobile subscriber is roaming. The short message centers used in mobile networks integrate SM-SC, GMSC and SM-IWMSC into one device, rather than implement these services by three independent physical devices. Therefore, the short message center hereinafter represents a network device integrated with SM-SC GMSC and SM-IWMSC.
The HSS/HLR is used for storing the data information of a mobile subscriber including routing information; the CGF/CDF is used for collecting and processing offline charging bill information of mobile subscriber and transferring the offline charging bill information to the charging center; the OCS is used for collecting and processing the online charging bill information of mobile subscriber and transferring the online charging bill information to the charging center.
The IP-SM-GW illustrated in FIG. 3 is a newly added network entity which facilitates the interworking between message protocols of IP network and the existing short message protocols of Wide-band Code Division Multiple Addressing/Globe System for Mobile Communication (WCDMA/GSM) network to implement communications between IP User Equipment (UE) and a GMSC/SM-IWMSC.
When using an immediate short message service, a UE based on Session Initial Protocol (SIP) has to register in an IP-SM-GW firstly; the IP-SM-GW notifies the HSS that the UE has registered and the address of IP-SM-GW; the HSS stores the state of IP subscriber as IP Connected, and stores the address of IP subscriber and the address of IP-SM-GW to which the IP subscriber has registered.
A variety of methods for establishing a secure connection between a UE and an IP-SM-GW have been proposed in the present standards, the methods include a manner based on the secure architecture of General Authentication Architecture (GAA), a manner based on the network architecture of IMS and a tunnel-based manner.
In the case of establishing a secure connection between a UE and an IP-SM-GW based on the network architecture of IMS, a process of an IMS-based calling subscriber UE registers in an IP-SM-GW is as shown in FIG. 4; the process includes the following steps.
Step 401. The calling subscriber UE establishes an IP connection (Establishment of IP connection).
Step 402. Upon establishing the IP connection successfully, the calling subscriber UE registers in an S-CSCF according to the IMS registering process (IMS Registration). Functional entities of I-CSCF and P-CSCF and information transmitted between the S-CSCF and an HSS will be involved in the IMS registering process, which will not be further described for brevity
Step 403. The S-CSCF checks initial filter criteria (iFC) information obtained from the HLR/HSS in the IMS registering process (Check iFC information).
Step 404. After an IMS registration is successful, the S-CSCF notifies, according to the iFC information, an IP-SM-GW that the UE has registered in the IMS domain (SIP REGISTER).
Step 405. The IP-SM-GW sends a registration request (IP-IWF-Register Req) to the HLR/HSS to register its own address information and an identifier of UE in the HLR/HSS.
Step 406. The HLR/HSS stores the address information of IP-SM-GW and the identifier of UE, and then returns an IP-IWF-Register Res to the IP-SM-GW.
Step 407. The IP-SM-GW returns an acceptance response (SIP 200 OK) message to the S-CSCF.
After a piece of UE has registered in an IP-SM-GW by the registering process illustrated in FIG. 4, a processing procedure that the UE implements a message service between an IMS-based calling subscriber and a traditional called subscriber is shown in FIG. 5; the processing procedure includes the following steps.
Step 501. A piece of UE registers in an S-CSCF according to the IMS registering process (SIP/IMS Registration/re-registration procedure).
Step 502. The UE sends a MESSAGE request to the S-CSCF based on a Session Initial Protocol (SIP) MESSAGE manner.
Step 503. The S-CSCF forwards the MESSAGE request to an IP-SM-GW according to iFC information.
Step 504. The IP-SM-GW returns to the S-CSCF an SIP 202 acceptance message indicating that the MESSAGE request has been accepted (Accepted).
Step 505. The S-CSCF forwards the SIP 202 acceptance message to the UE.
Step 506. After parsing the MESSAGE request, the IP-SM-GW forwards a short message parsed from the MESSAGE request to an SM-IWMSC using a standard Mobile Application Part (MAP) signaling (Forward message). The address information of SM-SC may be parsed from the Requested-Uniform Resource Identifier (R-URI) or the message body of the MESSAGE request.
Step 507. The SM-IWMSC forwards the short message to an SM-SC (Message transfer).
Step 508. The SM-SC sends a short message delivery report to the SM-IWMSC (Delivery report).
Step 509. The SM-IWMSC sends the short message delivery report to the IP-SM-GW.
Step 510. The IP-SM-GW sends the short message delivery report to the S-CSCF using the SIP MESSAGE.
Step 511. The S-CSCF sends the short message delivery report to the UE using the SIP MESSAGE.
Step 512. The UE responds to the short message delivery report by a 200 ok message.
Step 513. The 200 ok message is forwarded to the IP-SM-GW via the S-CSCF.
It can be seen from the above description that, when a calling subscriber having registered in an IMS network domain initiates an IMS-based immediate message service, the called subscriber may be a subscriber having registered in an IMS network domain or a subscriber having only registered in a traditional Circuit Switch/Packet Switch (CS/PS) network domain or network domain of other types. The called subscribers having registered in different network domains have different processes on the selection of called network domain and on the routing of subsequent message. However, related art only describes the processes in the case of the called side network being an IMS network domain and there is no description about the processes to send a message from an IMS-based calling side net domain to a called subscriber via such network domains when the called side network is a traditional CS/PS network domain or network domain of other types, which makes the interworking processes between an IMS-based message and a non-IMS-based message unclear, thereby the practicability of message interworking between an IMS-based message and a non-IMS-based message is low.